Electric fuel pump



Dec. 6, 1938. Q J, LAUER ET AL 2,139,370

ELECTRIC FUEL PUMP Filed April 23, 1957 2 Sheets-Sheet l {121072 gfizzef A? iffy LT @oweig Dec. 6, 1938.

C. J. LAUER ET AL ELECTRIC FUEL PUMP Filed April 25, 1937 2 Sheets-Sheet 2 Ill pacity, promptness Patented Dec. 6, 1938 UNITED STATES PATENT OFFICE EIECTRIC FUEL PUMP Carleton J. haciand Roy L. Bowers, Flint, Mich,

General Motors Corporation,

Detroit, Mich, a corporation of Delaware Application April as, 1937, Serial No. 138,485 4 can (01. 103-118) the fuel, flowing from the reservoir under the influence of reduced pressure, has had a tendency to vaporize under excessive heat conditions and it is one of the primary objects of the present invention to devise a fuel supply system which shall avoid the disadvantage of fuel vaporization and vapor lock which, in the case of an engine operated pump, has interfered with the delivery of liquid fuel to the float bowl of the carburetor.

Among other objects tobe attained are substantially noiseless operation, high pumping eain delivering fuel, comparatively low pump speed, an arrangement whereby faulty engine operation is avoided when liquid fuel becomes vaporized in the pipe line, an improved arrangement for freeing the fuel from foreign matter, and an improved means to insure lubrication of the motor shaft hearings in the case of an empty fuel tank.

Other objects and advantages will be understood from the following description:

In the drawings showing an illustrative embodiment of the invention;

Figure 1 is a transverse section through a gasoline tank of a motor vehicle showing the novel pump mechanism therein.

Figure 2 is a vertical section through a part of the pump mechanism.

Figure 3 is a similar section through the motor and pump assembly.

Figure 4 is a section on line 4-4 of Figure 3.'

Figure 5 is a section on line 5--5 of Figure 4.

Figurefi is a section line --5 of Figure 4.

Referring by reference characters to the drawings, numeral ll represents a fuel tank such a tank as is carried by a motor vehicle. The tank may include an upper part marked i3. There is also shown in the drawings provision for draining the tank at l5.

The invention contemplates the support of a combined motor and pump assembly and spacer from the top of the tank, the whole assembly to be located within the tank. For supporting the motor, pump, and spacer, there is provided a ring of rubber or the like i1 peripherally overlying the marginal wall IQ of a tank opening 2| A metallic ring 23 rests upon the rubber ring overthe wall I! and fastening means 25 clamp the parts in position asv shown.

The pump mechanism includes a motor and pump assembly designated as a whole by numeral 5 21 and it also includes. in the case of a large tank, a spacer 23. The spacer is as shown, a cylindrical member secured above and to the motor and pump assembly 21 by fastening means 3|. At the top of the spacer flange 33. A metallic ring overlies the inner peripheral edge'of the rubber ring I! and fastening means 31 serve to clamp the ring 35 and the rubber ring to the flange 33. It will be seen from 5 Figure 1 that the pumping mechanism as a whole. doesnot rest on the bottom of the tank but that it is wholly supported by the rubber ring iI. One advantage arising from this type of support is the prevention of noise which would occur if the motor vibrations were fled by the fuel carrying tank. The spacer '23 is formed internally with a vertical passage 39 extending to an opening ll adapted to be connected in any convenient way with a conduit for supplying the engine. communication between the passage 39 and the main chamber of the spacer. At the top of the spacer is an insulated post 40 for connection with a suitable wire not shown. for supplying electric 29 is an annular l0 transmitted to and ampli- Openings 43 and 45 afford 85 energy. From this post a wire 41 extends through 8 the spacer 29 to a post 49 whereby the energy is communicated to the motor.

The motor and pump assembly comprises a tubular shell 5| with a top cover 53. The tubular electric shell is formed with a base 55. The rotor element 86 51 of the motor is carried by shaft 53. This shaft is mounted in spherical bearings Bl. Preferably the bearings are of porous oil absorbing metal and are supplied with lubricant by saturated felt washers 53 located 53 and the base 55, the felt washers and bearings being secured by suitable retainers. The axial slot shown at the right of the felt washer of the upper bearing permits gasoline to saturate the washer. If, after standing gasoline level in the motor chamber falls below the level of the washer, the gasoline which is retained in the annular washer lubricates the upper bearing. The brush carrying plate 65 is spaced by a paper collar assembled with the base. A stand pipe H is pressfltted into an opening of the base. It extends through a somewhat enlarged opening 13 in the top cover 53 and into the lower end of passage 39.

within recesses of the cover 40 for some time, the 4.5

51. Bolts 59 hold the cover The base 55 is cast to form a recess constitut- 5g a 99. This chamber, as

an anti-friction support -what arcuate recess 93 cylindrical filtering screen I09. -verted cup II I is made fast to the side wall 5| ing the housing for a gear pump. A bottom cover forms a closure for thepump chamber. The motor shaft 59 beneath its lower bearing 0| is reduced in diameter as at 11, carries a gear 19 and its lower end rests on a ball II located in a recess of the cast cover 15. This ball provides and thrust bearing for the rotor element of the motor. Cooperating with gear 19 1s a gear 02 meshing therewith, the two gears constituting a gear pump having an inlet 93 and an outlet 05, the outlet leading to a space beneath the stand pipe 1|. A bottom closure 01 is secured to cover 10 and base II by fastening means '09, there being a gasket between parts 15 and 81 as shown at 9i. A someis shown formed in the a suitable opening 95 in in communication with stand pipe. The recess cap 91. By means of cover 15, this recess is the space 05 beneath the 93 leads to an opening plate 15 and through said opening to a chamber shown in Figure 5, is located between walls 15 and 55 and is surrounded by a fire screen IOI whereby the chamber is separated from the larger region between parts 15 and 55. The flow of fuel to the chamber 99 is resisted by a valve disc I08 held against the seat I05 located I01, the latter being positioned by guides I00.

Between the parts 91 and B5 is a vertical walled A hollow inand extends down outside the screen I09 but terminates above the bottom of the lower face of the pump gears. A small opening H3 is provided near the top 'of the screen I09 within the cup III.

In the operation of the device, the motor drives the gear pump which'takes fuel from the tank through the filtering screen I09 and the inlet 89. It delivers the fuel to the outlet 86 whence the fuel travels up through the stand pipe 1|. Fuel overflows from the stand pipe at 13 and fills the motor chamber. It then fills the passage 39 and the larger chamber of thespacer. In

so filling these chambers the air is forced through thev outlet 4|. This filling of the chamber requires but a few seconds. Thereafter the fuel is delivered through outlet 4| to the carburetor of the engine. The use of a gear pump is of considerable importance inthat it may be driven that the 'efliciency of the pump is such as to overcome the pressure of any vapor developed in the system. When the car is stopped there is an ample supply of fuel in the stand pipe and within the overlying chambers to keep the pump chamber full of fuel. It is to be noted that the bearings for shaft 59 are substantially fluid tight.

This is ofparticular importance in connection with the lower bearing. Such a quantity of fuel is carried by the motor chamber that the bearings are supplied with lubricant for many hours after the tank is empty for the reason that the lower bearing effectively resists the escape of fuel.

Inasmuch as the pump must supply fuel for I maximum demands,

the excessive delivery of the pump under normal driving conditions results in a flow of fuel through the by-pass. In the event that the car is stopped and the pump becomes 91 formed in the cover within opening 91 by'a spring idle it is possible that vaporized fuel might force all the liquid fuel from the pump and also force it out through the valve I03 and the screen I II into the space within the filter I 00. This it would do rather than flood the carburetor.

-Un der some circumstances it might happen that the fuel vapor would remain within the filtering screen I09.

the rotating parts. This is Owing to the anti-friction 11 and the ball the ball bearing u. contact between shaft in fuel even after the tank is drained. This is true because there is substantially no leakage about the lower bearing of shaft I9. The bearings for the rotor are thus always plentiiully supplied with lubricant, sufiicient for a long period of time after the fuel in the tank is exhausted.

The by-pass and its valve are located substantially at the bottom of the tank so that no turbulence or aeration can occur. If a car so equipped were left standing for months there propagation to the fuel in It should be added that in the case of a shallow tank the spacer may be omitted. When so omitted an outlet such as M in Figure 2 will be provided at the top of the motor unit and the stand pipe will be in open communication therewith as it is in open communication with the passage 39 in Figure 2. In other respects the arrangement for a small tank will be the same as above described.

We claim:

1. In combination, a fuel motor and pump assembly, means to support said assembly from the top of said tank, said assembly including a pump 'and a superposed motor, said motor being located within a motor chamber, said motor chamber having upper and lower end walls, means to rotatably support the rotor of said motor in said end walls, the rotatable support in the lower end wall being' constructed to minimize escape of liquid, a stand pipe forming the discharge passage of said pump, said'stand pipe having its upper end open to the motor chamber means to admit fuel from the delivery end of the stand pipe into the top of the motor chamber whereby the latter may be supplied with fuel from the pump for lubrication and whereby the lubricating medium may be retained in said chamber when the pumpis idle,

tank, a combined and other means whereby the fuel may be dellvered externally from the stand pipe.

2. The invention defined by claim 1 together with a spacer above said motor and pump assembly and secured thereto, said spacer secured to the top of said tank and housing said other means.

3. The invention defined by claim 1, said pump I comprising a first gear carried by an extension 10 of the lower end of the rotor shaft of said motor, said assembly including a cover rigid therer with and an anti-friction thrust bearing in said cover engaged by the end of said rotor shaft extension.

4. The invention defined by claim 1, said supporting means for said assembly including a resilient ring secured to said tank and to said assembly.

CARLEION J. LAUER. ROY L. BOWERB. 

